The present invention relates to apparatus for use by dental practitioners, specifically dentists, dental hygienists, dental therapists, oral surgeons, and the like. The present invention provides an apparatus which retracts dental tubing or cabling which is attached to or associated with various dental instruments used by the dental practitioner, when the dental instruments are not in use. However, when the dental instruments are to be used by the dental practitioner, and are removed from a holder therefor, the associated dental tubing or cabling is released from its retracted position so that it may be pulled into place at the dental work site by the dental practitioner.
Typically, dental practitionersxe2x80x94most usually dentists and dental hygienists and the likexe2x80x94employ a number of different dental instruments while performing many different dental procedures on their patients. Several of those dental instruments might be used at one time, for example a turbine and a suction device, x-ray or video camera devices together with a suction device, and so on. Typically, there may be four or as many as eight such devices that may be employed by the dental practitioner, and they are arranged in a cabinet which is placed either at the head of the patient when the patient is in a dental chair, or at the side of the patient when the patient is in a dental chair. The practitioner will work on the patient while standing or sitting beside the patient at either side or at the top of the patient""s head; and the various instruments will be employed by the dental practitioner by being brought to the dental work site in the patient""s mouth with their associated dental tubing or dental cabling being placed beside the head or beside the shoulder of the patient.
However, when the dental practitioner no longer wants to use the dental instrument, he or she will place the dental instrument back into the holder on the cabinet, together with the other dental instruments which may be employed. Unfortunately, each of those dental instruments is associated with dental tubing or cabling, and unless that dental tubing or cabling is retracted into the cabinet, it could get tangled with other dental tubing or cabling, or it could become a hazard over which the dental practitioner or a dental assistant could trip. Moreover, if the dental tubing or dental cabling becomes entangled or snarled, and a circumstance arises where the dental practitioner suddenly and quickly requires the use of one of the dental instruments, it may be possible that the dental instrument is not available immediately due to the entanglement of its respective dental tubing or dental cabling with the dental tubing and dental cabling of other instruments.
The present invention provides a simple and effective solution to the problem of retracting and releasing dental tubing and dental cabling, by taking advantage of certain facts relating generally to the practice of dentistryxe2x80x94at least as it is known in North America. Specifically, the present invention acknowledges that modem dental instruments are provided which either are associated with pneumatic tubing, hoses, and the like, or certain dental instruments may be associated with optical fibre. In either case, the dental tubing or cabling is flexible. Also, when dental tubing is employed, as noted, it will either be connected to a source of suction; and more particularly, for dental instrumentation required for drilling or polishing, and the like, all such instrumentation is pneumatically driven. Belt driven instrumentation is no longer employed.
Thus, it is convenient in the organization of a dental practitioner""s operatory to gather all of the dental instruments which will be employed into a single cabinet, located beside or at the head of the patient, as noted above. That cabinet will be connected to a source of pneumatic pressure; and that fact is employed by the present invention.
The present invention also provides fail-safe operation. That is, if there is a source of pneumatic pressure whereby the dental practitioner can practice dentistry on patients, then that same source of pressure can be employed to ensure that the dental tubing and dental cabling associated with unused dental instrumentation at that instant in time is, indeed, retracted. If there is a failure of the source of pneumatic pressure, then the retraction of the dental tubing and dental cabling is relieved.
Still further, because a source of pneumatic pressure will be associated with the cabinet in which the dental tubing and dental cabling for the various dental instrumentation is to be retracted, the holder for each specific dental instrument can be associated with the source of pneumatic pressure in such a manner that when the respective dental instrument is removed from its holder, the respective dental tubing or dental cabling is released. This comes about as a consequence of the use of single-ended or single-acting pneumatic cylinders, which require connection to a source of pneumatic pressure if the cylinder rod or piston within the cylinder is to be extended. Immediately upon the release of pneumatic pressurexe2x80x94that is, immediately when the single-acting pneumatic cylinder is disconnected from the source of pneumatic pressurexe2x80x94the cylinder rod is free to move axially within the cylinder, without any appreciable resistance.
All of these matters are discussed in greater detail hereafter.
A number of prior art approaches are known, by which dental cabinet appliances, retractors, and the like, are provided. They include the following:
Suter Canadian Patent 1,111,679, issued Nov. 3, 1981, teaches a dental unit which is intended to position dental instruments at a location which is convenient to a seated or standing dentist. In particular, a four-bar linkage is provided which swings a holder for various dental instruments from a low stored position to an in-use position. In the lower position, the dental instruments are convenient to a seated dentist; in the higher position, the instrument holder is convenient to a dentist who is standing. However, there is no consideration given to the associated dental tubing or cabling for the various dental instruments.
Japanese Patent abstract 62133308, published Dec. 7, 1988, teaches a dental apparatus whose purpose is to make the delivery of the flexible hose for a handpiece sufficiently long, by providing a flying arm which tilts forwardly. The flexible hose is delivered forwardly while sliding through an elongated hole in a base, and thence through a hole on the flying arm. The purpose is to permit the flexible hose to be extended while reducing the space in which the apparatus is stored.
Another Japanese Patent Abstract, 05334135, published Jul. 25, 1995, teaches a device which winds instrument hose or tubing, wherein a pulley and block moves along a guide, with the instrument hose being wound around a pulley.
U.S. Pat. No. 3,372,883 issued Mar. 12, 1968 to Ota, teaches a rotatable apparatus that is employed to pay out or draw in dental hoses. Means are provided to bias the rotatable apparatus in one direction about the rotation axis, so as to thereby draw in the hose.
Wahler et al U.S. Pat. No. 3,487,850, issue Jan. 6, 1970, teaches a similar device where the flexible hose is wound onto a pulley-like arrangement which is spring biassed so as to return the hose to a storage position.
McGaha U.S. Pat. No. 3,514,171, issued May 26, 1970, teaches a dental instrument cabinet and storage mechanism in which a partitioned and compartmented housing has a plurality of individual compartments into each of which a separate instrument and connecting hose means may be stored. The compartmented storage means is slidably mounted in the interior of the housing and is pulled out from the housing when it is desired for the instruments to be used.
U.S. Pat. No. 3,693,258, issued Sep. 26, 1972 to Fulton et al teaches a retractor for a dental handpiece, where the retractor is equipped with a spring-supported weight which trips the release mechanism of the retractor when the hose is pulled abruptly. The dentist may select the length of the hose; and when the dentist wants the hose to be retracted, an abrupt pulling force upon the hose causes the hose to be retracted back into a cabinet.
Roland U.S. Pat. No. 3,895,764 issued Jul. 22, 1975, teaches a retracting device whose purpose is particularly to deliver and retrieve multichanneled hose as used by a dentist. The hose is wound onto a collecting reel; means are provided to ensure that the hose will not crimp or kink during the retrieving action.
Another patent issued to McGaha, U.S. Pat. No. 4,114,273, issued Sep. 19, 1978, teaches a very complicated console for extending and retracting operating flexible hoses, particularly in cases where the instrumentation is placed in an over-the-patient position. The extending and retracting of the flexible hose is controlled by a pawl and ratchet mechanism.
Hirth U.S. Pat. No. 4,151,648 issued May 1, 1979, teaches a dental apparatus which retracts supply hoses, and which employs a coil spring. The hose is interposed between windings of the spring, and when the hose is extended, the radius of the coil contracts, which causes control switches to be activated. A ratchet is employed to prevent unwanted retraction. When the ratchet is released, the coil spring expands thereby drawing the hose back into the housing.
Another device for storing dental handpieces is taught in Heuback U.S. Pat. No. 4,470,811 issued Sep. 11, 1984. Here, the hose for each dental handpiece is permitted to hang freely in a loop-like fashion, where a guidance roller together with another element guide the hose during movement of the handpiece from the stored position to an extended position. No attempt is made to retract or hide the dental tubing into a cabinet; and thus the housing is generally one which is employed in a relatively high position compared to the position of the patient.
Hamula U.S. Pat. No. 5,450,874, issued Sep. 19, 1995, teaches a device which retracts and stores a length of dental instrumentation hose. Here, the length of hose is anchored at one end and is routed under a spool and through an opening of an instrument panel. The hose hangs in a loop or bight with the spool supported on the bight, and the hose is kept under tension by the weight of the spool. When the dental instrument is to be used, the spool is lifted onto and secured by supports, and tension is thereby released from the hose. Then, a quick jerk or pull on the hose dislodges the spool from its support, causing it to fall vertically into the compartment and drawing the hose back into the compartment with it.
Another flexible hose assembly which employs weights is taught by Upton in U.S. Pat. No. 5,775,354, issued Jul. 7, 1998. However, in this case, the weights do not interact with the dental hose per se. A xe2x80x9cblock and tacklexe2x80x9d arrangement is provided, where the counterweights are at least partially immersed in a damping liquid. The purpose is to prevent hose snap-back. It should be noted, however, that the hoses are of the sort generally used in automobile repair and service centres, of the sort that may deliver water or air to the mechanic working on a vehicle.
Finally, Behringer U.S. Pat. No. 5,873,717, issued Feb. 23, 1999, teaches another device where supply hoses are essentially permitted to hang free. The purpose is to preclude activation of a dental handpiece until such time as it has been lifted away from a holder.
The present invention provides an apparatus for selectively retracting and releasing dental tubing and dental cabling, whereby the dental tubing and dental cabling is retracted into a cabinet when it is not in use, and is released so as to be extended to a work site when in use. The apparatus comprises the following:
First, there is a single-acting pneumatic cylinder having a cylinder rod which is freely moving axially within the cylinder when the cylinder is disconnected from a source of pneumatic pressure. The cylinder rod is extended from the cylinder when the cylinder is actuated by being connected to a source of pneumatic pressure.
There is an actuator arm connector which is secured to the outer end of the cylinder rod, and is movable therewith.
An actuator arm having first and second ends is pivotally connected at its first end to the actuator arm connector. The second end of the actuator arm has a guide loop pivotally attached thereto.
There is also provided a pneumatic actuator switch which is mounted on the cabinet for selective actuation of the pneumatic cylinder.
The actuator arm is pivotally mounted on a pivot axis which is located at a point intermediate the first and second ends thereof. The mounting is such that when the pneumatic cylinder is actuated by being connected to source of pneumatic pressure, the second end of the actuator arm is located at a position behind the pivot axis. Also, when the pneumatic cylinder is deactivated by being disconnected from a source of pneumatic pressure, whereby the cylinder rod is freely axially movable within the cylinder, the second end of the actuator arm may be located at a position which is in front of the pivot axis.
A length of dental tubing or a length of dental cabling is passed through the guide loop in such a manner that when the pneumatic cylinder is actuated by the pneumatic actuator switch connecting the pneumatic cylinder to a source of pneumatic pressure, the guide loop is behind the pivot axis and the dental tubing or dental cabling is retracted into the cabinet within which the apparatus is mounted. When the pneumatic cylinder is deactivated by being disconnected by the pneumatic actuator switch from the source of pneumatic pressure, the dental tubing or dental cabling may be withdrawn from the cabinet so as to be extended to a work site by a dental practitioner.
Typically, the guide loop is formed of a smooth, plastics material.
Also, typically there is a wrap bar which is located in the cabinet below and in front of the pivot axis. The dental tubing or dental cabling is passed in front of the wrap bar when the pneumatic cylinder is actuated.
The apparatus of the present invention may further include a pneumatic safety cut-off switch, whereby the pneumatic cylinder may be deactivated by selectively placing the pneumatic safety cut-off switch in its cut-off position.
In that case, it is usual that the pneumatic safety cut-off switch is physically associated with the pneumatic actuator switch.
In the apparatus of the present invention, any dental instrument may be associated with the dental tubing or dental cabling, and the dental instrument is placed into the pneumatic actuator switch when it is not in use.
The pneumatic actuator switch is normally activated when the dental instrument is placed therein, and it is deactivated when the dental instrument is removed therefrom.
Thus, when the dental instrument is placed in the pneumatic actuator switch, the switch is activated so as to actuate the pneumatic cylinder, and so as to retract the dental tubing or dental cabling into the cabinet.
On the other hand, when the dental instrument is removed from the pneumatic actuator switch, the switch is deactivated so as to deactuate the pneumatic cylinder, and so as to permit the dental tubing or dental cabling to be extended away from the cabinet, to a work site.
In the circumstances wherein a length of dental tubing is associated with a pneumatically operated dental instrument, that pneumatically operated dental instrument will be pneumatically parallel to the pneumatic cylinder, and the parallel pneumatic cylinder and pneumatically operated dental instrument are pneumatically in series with the pneumatic activator switch and a source of pneumatic pressure.